A few thoughts on the use of PLB/SPOT
Two climbers’ distress call

Interesting. The article linked references the SPOT device, which as I understand uses their proprietary network of satellites.

Majid, do you know anything about the COSPAS-SARSAT 406Mhz distress beacons (like the ACR Resqlink series)? In terms of the limitations of signal bouncing in a unique environment? They're standard for marine use but I hadn't considered the issues of their use in more complex terrain (valleys, peaks, walls, etc).

"What incident?"

Word incident is defined as "an event or occurrence". The blurb certainly qualifies as both an event and occurrence.

I understand that the message of the article was not emphasized enough. Simply put - if a person activates PLB/SPOT, they should not turn it off to "save batteries".

The biggest problem with GPS enabled PLBs and SPOT is that they are one way communication devices. That is - they are simple transmitters of signal, they have no way of knowing whether the signal was received and whether it was received correctly or not - one of the reasons why they keep transmitting for extended periods of time to increase the odds of satellites picking up their transmissions.



ACR has FAQs on how PLB operates and what happens when they get activated.

As to reaction times - it varies depending on location. A quick internet search yields an account of bear mauling in Alaska, and subsequent response. In short, in under 10 minutes SAR services new the exact location of incident, but failed to respond effectively due to organizational issues.

I just returned from a conference which included discussion on PLB spot and SARSAT and there is defiantly an improvement on the technology . First off, you have radio signal that send the signal from PLB or SPOT to SAT and internal receiver signal that picks GPS SAT signal and pin points your location.

if you are on a face of a mountain and turn a spot or PLB on, first, the GPS receiver inside the PLB/SPOT needs to gather info on where about you are then transmit this info or( pocket of data) up to over passing SAT in the sky. if PLB transmit signal without GPS coordination, the passing SAT will ask where you are and if PLB or SPOT does not have this data then SAT bye byes and goes off till next SAT comes over and again asks if GPS coordinates are available and if so, then coordination and radio signal as pair is matched and send by SAT to dispatch.

From there, the data is cleaned up and reviewed by either desk officers(gov agents) or privet low IQ agent in some privet company and relayed to rescuers. The big issue is accuracy of internal GPS signal off PLB or SPOT when it goes up to SAT. Since GPS signal comes off from another group of SATs in sky and then PLB signal transmit up to a different group of SAT in sky , almost anything is possible and this data can go off .

Now,In flat ocean with no mountains around,sending GPS and radio coordination over to SAT is totally different and probably more effective than mountains and canyons.

Even if you have accurate coordination and positivity people know where you are, in reality,there is no grantee on successful rescue but unfortunately, many companies are selling these devices and people are pushing their limit in tothe red zones on a wrong assumption that they can turn the switch on and expect a helo over their head in 30 min.

If you have one of these toys and decided to turn it on, make sure you get your plan B and plan C going at the same time cause that helo is not coming in 30 min.

Now, from very recent and very personal experience, let me tell you one more thing. I activated a PLB when a partner was not breathing. That was in a storm that although a helicopter was airborne in less than 30 mins, it was unable to reach us because of weather. We revived the injured person and self extricated to the trailhead. There we were met by a full emergency team who assured us that the PLB activation was a good response allowing them to follow up on the injuries.